Land mine



Nov. 2, 1954 Filed NOV. 6, 1951 H. H. JoHNsoN LAND MINE 2 Sheets-Sheet lFVG. 3.65

/ l l l l l l l l l l l l l INVENTOR H4204@ H. JoH/vso/v,

fm/naman v ,49mm

ATTORNEYS Nov. 2, 1954 l H H JOHNSQN 2,693,147

LAND MINE Filed NOV. 6, 1951 Y 2 Sheets-Sheet 2 INVENTOR Hneo H dof/SOMBY Q/Qyz/M//wmvmm ATTORNEYS United States Pate This invention relates toland mines, and more particularly to a non-magnetic land mine having anon-detachable fuse.

lt is among the objects of the invention to provide a land mine havingno parts of magnetic material, such as metal; which has a non-detachablefuse and tiring mechanism disposed within the casing or shell of themine; which uses a receptacle of compressed air for the ring spring;which can be armed and disarrned as desired; and which is simple anddurable in construction, readily adaptable to mass production, andpositive and elfective in operation.

Other objects and advantages will become apparent from a considerationof the following description and appended claims in conjunction with theaccompanying drawings, wherein:

Figure 1 is a side elevational View of a land mine illustrative of theinvention;

Figure 2 is a cross-sectional view on an enlarged scale on the line 2--2of Figure l;

Figure 3 is a cross-sectional view on the line 3 3 of Figure 2;

Figure 4 is a cross-sectional View on the line 4 4 of Figure 3;

Figure 5 is a fragmentary cross-sectional view on an enlarged scale onthe line 5 5 of Figure 4; and

Figure 6 is a fragmentary cross-sectional View on the line 6 6 of Figure5.

With continued referencel to the drawings, the land mine comprises areceptacle, generally indicated at 10, having an annular and preferablycylindrical side wall 11 and a flat bottom wall 12 enclosing thereceptacle at one end of the side wall, the other end of the receptaclebeing open. The side wall 11 is provided adjacent the open end of thereceptacle with an internal annular groove 13, and the portion of theside wall between this groove and the end of the side wall at the openend of the receptacle is provided with spaced apart notches 14 providinginwardly directed and spaced apart tongues 15 betlween the groove 13 andthe adjacent end of the side wa A cover 16 in the form of a ilat disc isprovided with a central aperture or opening 17, and with peripheralnotches providing tongues 1S spaced apart distances equal to the widthof the tongues 15 on the side wall and having a width substantiallyequal to the width of the notches between the tongues 15, so that thetongues on the cover can be passed through the notches in the side wallof the receptacle and, upon a slight rotation of the cover relative tothe receptacle, engage under the tongues on the receptacle side walls toreleasably lock and cover to the side wall, ln the arrangementillustrated, the groove 13 has a width somewhat less than the thicknessof the cover 16, and the tongues 18 on the covers have a thicknesssubstantially equal to the width of the grooves and less than thethickness of the remainder of the cover, and a gasket 19 of resilientmaterial is disposed between the marginal portion of the cover 16 andthe side of the groove 13 remote from the adjacent end of the side wall11 of the receptacle. Spaced apart recesses 20 are provided in the cover16 and open through the top or outer surface of the cover for receivingthe pins of a spanner wrench by means of which the cover can be rotatedrelative to the receptacle.

The receptacle 1l) and cover 16 are formed of a nonmagnetic material,such as tempered glass, and a tube 21 of the same material extends fromthe inner side of the tube.

2,693,147 Patented Nov.. 2, 1954 end wall 12 at the center of the latterinto the opening 17 in the cover 16, but does not extend entirelythrough the cover.

While the tube 21 has been described as formed of tempered glass, thesame as the receptacle and the cover, it is to be undertsood that thistube may be formed of other material, such as synthetic resin plastic,if found more convenient, without in rany way exceeding the scope of theinvention.

The tube is provided intermediate its length with an aperture 22, and isprovided between the aperture 22 and the bottom wall 12 of thereceptacle with a series of angularly spaced apart apertures 23 whichmay be somewhat smaller than the aperture or opening 22.

A pair of lugs 24 and 25 project perpendicularly outwardly from the tube21, one at each side of the opening 22 in spaced apart and substantiallyparallel relationship to each other and together constitute a bracketfor pivotally supporting a lever 26. The lever 26 is in the form of ailat bar disposed between the lugs 24 and 25, and is pivotally mountedon the lugs by a pivot pin 27 which extends through registeringapertures in the lugs adjacent the outer ends of the latter and in thelever 26 intermediate the length thereof. The lever extends through theopening 22 and has one end disposed in the tube 21.

A fuse and tiring mechanism assembly, generally indicated at 30, ismounted on the inner side of the bottom wall 12 of the receptacle belowthe outer end of the lever 26, and a link 31 connects the outer end ofthe lever 26 to the tiring mechanism.

The firing mechanism, as particularly illustrated in Figure 5, comprisesa lirst tube 32, preferably formed of glass, having one end seated in arecess in a lug 33 projecting upwardly from the bottom wall 12 of thereceptacle. The lug 33 has an opening 34 therein substantiallyconcentric with the recess in which the tube 32 is received, and anabutment formation 35 is disposed adjacent the side of the lug 33 remotefrom the recess therein and supports a plate 36 having an aperturetherein, and a tiring cap or detonator 37 mounted in the aperture in theplate 36 in registry with the opening 34 in the lug 33. At its other endthe tube 32 is telescopically received in one end of a second tube 38 ofsomewhat larger diameter than the tube 33, and the tube 38 is providedwith diametrically opposed projections received in the internal groovesof a pair of grooved brackets 39 and 40 projecting upwardly from theinner surface of the bottom wall 12 of the receptacle. The projectionson the tube 33 and the grooved brackets 39 and 4l) are provided withregistering apertures which receive dowel pins 41 and 42 whichpositively hold the tube 38 in predetermined positions relative to thebottom wall 12 of the receptacle, the end of the tube 32 remote from thetube 38 being positively held in predetermined positions relative to thebottom wall by the lug 33.

A tiring pin 45 of non-magnetic material is slidably mounted in the boreof the tube 32 and has a pointed end 46 directed toward the detonator37. This ring pin is provided in its other end with a recess whichreceivels a weight 47 of a suitable heavy, non-magnetic materia A pairof arms 48 and 49 are mounted on the tube 32 at respectivelydiametrically opposite sides of the tube and are secured to the tube atcorresponding ends by suitable means, such as band or ring 56, extendingthrough apertured lugs on the arms and surrounding the At their otherends the arms 43 and 49 are provided with perpendicularly extendingtongues which project through apertures in the tube and engage theopposite sides of the tiring pin 45 to releasably hold the ring piu atthe end of the tube 32 remote from the detonator 37.

A lug 52 extends upwardly from the inner side of the bottom wall 12 at alocation spaced from the brackets 39 and 40 in a direction away from thelug 33, and an abutment block 53 is pivotally mounted on the end of thelug 52 remote from the bottom wall. A small flask 55 has one endreceived in the abutment block 33 and engages the adjacent end of thetube 33 near its other end. This ask is provided in its end disposedwithin the tube 38 with a formation 56 providing a vent opening and avalve seat surrounding the vent opening, and a valve is mounted in thetube 38 adjacent this end of the flask.

The valve comprises an elongated body 57 pivotally mounted in the tube38 by a pivot pin 58 which extends transversely through the body and isreceived at its ends in notches 59 provided in the tube 38. A valvewasher 60 of rubber or other suitable resilient material is pivotallymounted on the body 57 at the end of the latter adjacent the ask 55 andheld in sealing engagement with the valve seat formation 56. The body 55contains compressed air when the mechanism is in operative condition,which air may be admitted to the body through an opening normally closedby a Suitable plug or check valve 61, and is held in the body by thevalve washer 60.

Near its end remote from the lever 26, the link 31 is provided with anotch 62 in which the valve body 57 is engaged at its end remote fromthe washer 60.

With this arrangement, if the ond of the lever 26 within the tube 21 ismoved toward the bottom wall 12 of the receptacle 1t), the link 3l willpull on the end of the valve body 27 engaged thereby rotating the valvebody about the pivot pin 5S and withdrawing the valve washer 60 from theadjacent end of the flask 55 and permitting the compressed air to escapefrom the flask into the tube 38. The compressed air from the ask willact on the tiring pin 45 and force this firing pin through the tube 32and against the detonator 37 detonating the latter and firing theexplosive charge 63 disposed in the receptacle 1.0 around the tube 21. Asuitable vent 64 is provided in the tube 32 adjacent the detonator 37 toprevent the ring pin 45 from becoming airlocked in the tube.

A stem or plunger 65, preferably of cylindrical shape and formed of anon-magnetic material, is received in the tube 21 and has a notch orrecess 66 intermediate the length thereof in which the end of the lever26 projecting into the tube 21 is received. This notch 66 is connectedat one side to the end of the stern adjacent the bottom wall 12 of thereceptacle by a groove 67, the groove and recess 66 togetherconstituting a bayonet slot connection so that the stem can be moveddownwardly past the inwardly projecting end of the lever 26 and thenslightly rotated to engage the inwardly projecting end of the lever inthe recess.

Deformable or breakable stop members 68 are secured to the outer side ofthe tube 21 and project through the apertures 23 in the tube intoengagement with they end of the stem 65 adjacent the bottom wall of thereceptacle and hold the stem against movement inwardly of the tube anamount suflicient to move the lever 26 and release the above-describedring mechanism until these stop members 68 are subjected to apredetermined force exerted on them by the stem.

The stem 68 projects through the central opening 17 in the cover 16, anda tread plate 70 in the form of a thin disc of non-magnetic material issecured at its center to the corresponding end of the stem and is spacedoutwardly from the outer side of the cover 16. This tread plate 70 hasan annular marginal flange 71 which projects substantiallyperpendicularly from the plate and overlaps the outer side of the sidewall 11 of the receptacle adjacent the open end oi the latter.

Compressible elements 72 formed of a suitable resilient material, suchas sponge rubber, are disposed between the cover and the tread plate 70and hold the tread plate in spaced relationship to the cover until theyare subjected to suicient force to compress them and permit the treadplate to move toward the cover.

The bracket lugs 24 and 25 are provided with mutually registeringapertures between the pivot pin 27 and the adjacent side of the tube 2i,and the lever 26 is provided with an aperture registering with theseapertures in the lugs when the lever is in its non-firing position. Theside wall lll of the receptacle is provided with an aperture 74 inalignment with the above-described apertures in the lugs 24 and 25 andthe lever 26, and an elongated safety pin 75 extends through theaperture 74 in the side wall of the receptacle and through the lugs 24and 25 and the lever 26 at a location between the pivot pin 27 and theadjacent side of the tube 21 to hold the lever 26 against movement. Whenthe safety pin 75 is in place, the mine is unarmed,'and when the stem 65 is positioned in they tube 21 in engagement with the lever 26 and thesafety pin 75 is withdrawn, the mine is armed 4 and ready to lire whensuiicient pressure is exerted on the tread plate 70.

In order to disarm or unarm the mine, the safety pin 75 is reinsertedthrough the lugs 24 and 25 and the lever 26 to hold this lever againstmovement and the tread plate 70 is then slightly rotated and pulled awayfrom the cover 16 to remove the stem 65 from the tube 21, the inwardlyprojecting end of the lever 26 passing through the notch 67 in the stemas the latter is removed from the tube.

The invention may be embodied in other specific forms without departingfrom the spirit or essential characteristics thereof. The presentembodiment is, therefore, to be considered in all respects asillustrative and not restrictive, the scope of the invention beingindicated by the appended claims rather than by the foregoingdescription, and all changes which come within the meaning and range ofequivalency of the claims are, therefore, intended to be embracedtherein.

What is claimed is:

l. A non-magnetic land mine comprising a receptacle having an annularside wall open at one end and a bottom wall closing the other endthereof, a fiat cover closing the open end of said receptacle, said sidewall having locking formations at the open end of said receptacle andsaid cover having a central opening therein and peripherally disposedlocking formations engageable with the locking formations on said sidewall for releasably locking said cover to said receptacle uponrotational movement of the former relative to the latter, a tubeextending from said bottom wall into the central opening in said coverand having an opening therein intermediate length thereof, a bracketextending laterally from said tube adjacent the opening therein, a leverpivotally mounted intermediate its length on said bracket and having oneend disposed within said tube, a firing mechanism mounted on said bottomwall, a link connecting the other end of said lever to said firingmechanism for releasing the latter when said one end of said lever ismoved toward said bottom wall, a stem extending through said tube andengaging said one end of the lever, a tread plate mounted on one end ofsaid stem and spaced outwardly from said cover, and deformable meanscarried by said tube and engaging said stem resisting movement of saidstem toward said bottom wall until subjected to a predetermined force,all of said parts being formed entirely of non-magnetic materials andsaid mine being en tirely free of metallic parts.

2. A land mine comprising a receptacle having an open end and a bottomwall closing the other end thereof, a dat cover detachably secured tosaid receptacle in closing relationship to the open end of the latterand having a centrally disposed opening therein, a tube extending fromsaid bottom wall into the opening in said cover, a stern slidablymounted in said tube and extending at one end through said cover, atread plate mounted on said one end of said stem and spaced outwardlyfrom said cover, deformable means carried by said tube and engaging saidstem to releasably hold the latter at a predetermined positionlongitudinally of said tube, said tube having an opening intermediatethe length thereof and said stem having a recess therein registeringwith the opening in said tube, a bracket projectinfr outwardly from saidtube adjacent said opening, a lever pivotally mounted intermediate itslength on said bracket and extending at one end through the opening insaid tube into the recess in said stem, tiring mechanism mounted on theinner side of said bottom wall, and a link connecting the other end ofsaid lever to said ring mechanism for releasing the latter, said firingmechanism including a tube, a detonator disposed at one end of saidtube, a compressed air ask disposed at the other end of said tube andhaving a valve seat formation within said tube, a valve mounted in saidtube in engagement with said valve seat formation and connected to saidlink for releasing compressed air from said ilask into said tube whensaid stern is moved toward said bottom wall beyond said predeterminedposition, and a ring pin slidably mounted in said tube between saidvalve and said detonator, all parts of said mine being of non-magneticand said mine being entirely ree of metallic components.

3. A non-magnetic land mine comprising a receptacle havmg an open endand a bottom wall closing its other end, a` cover releasably secured tosaid receptacle in closing relationship to the open end of the latterand having an opening therein, a tube extending from the bottom wall ofsaid receptacle into the opening in said cover and having an openingtherein between said bottom Wall and said cover, a stem mounted in saidtube for longitudinal movement relative thereto and projecting at oneend through the opening in said cover, said stem having a recess thereinintermediate the length thereof, a tread plate mounted on said one endof said stem in spaced relationship to said cover, means acting betweensaid stem and said bottom Wall maintaining the recess in said stem at apredetermined position relative to the opening in said tube until saidtread plate is subjected to a predetermined force, firing mechanismmounted on said bottom wall and including a compressed air flask havinga discharge opening in one end and a movably mounted valve closing thevent opening in said ask, a bracket mounted on said tube adjacent theopening in the latter, a lever pivotally mounted intermediate its lengthon said bracket and having one end engaged in the recess in said stem,and a link connecting the other end of said lever to said valve, saidmine being entirely free of magnetic materials.

4. A non-magnetic land mine comprising a receptacle having an open endand a bottom Wall closing its other end, a cover releasably secured tosaid receptacle in closing relationship to the open end of the latterand having an opening therein, a tube extending from the bottom wall ofsaid receptacle into the opening in said cover and having an openingtherein between said bottom wall and said cover, a stem mounted in saidtube for longitudinal movement relative thereto and projecting at oneend through the opening in said cover, said stem having a recess thereinintermediate the length thereof, a tread plate mounted on said one endof said stem in spaced relationship to said cover, means acting betweensaid stern and said bottom wall maintaining the recess in said stem at apredetermined position relative to the opening in said tube until saidtread plate is subjected to a predetermined force, firing mechanismmounted on said bottom wall and including 'a compressed air ask having adischarge opening in one end and a movably mounted valve closing thevent opening in said ask, a bracket mounted on said tube adjacent theopening in the latter, a lever pivotally mounted intermediate its lengthon said bracket and having one end engaged in the recess in said stem, alink connecting the other end of said lever to said valve, said leverand said bracket having apertures therein between said lever and saidbracket, which apertures are in registry when the recess in said stem isin said predetermined position relative to the opening in said tube andsaid receptacle having an aperture therein in alignment with theapertures in said bracket, and an elongated pin extending through theapertures in said receptacle, said bracket and said lever to hold saidlever against movement relative to said bracket, said pin beingremovable to arm the mine, said mine being entirely free of magneticmaterials.

5. A non-magnetic land mine comprising a receptacle having an open endand a bottom Wall closing its other end, a cover releasably secured tosaid receptacle in closing relationship to the open end of the latterand having an opening therein, a tube extending from the bottom wall ofsaid receptacle into the opening in said cover and having an openingtherein between said bottom Wall and said cover, a stem mounted in saidtube for longitudinal movement relative thereto and projecting at oneend through the opening in said cover, said stem having a recess thereinintermediate the length thereof, a tread plate mounted on said one endof said stem in spaced relationship to said cover, means acting betweensaid stem and said bottom wall maintaining the recess in said stem at apredetermined position relative to the opening in said tube until saidtread plate is subjected to a predetermined force, tiring mechanismmounted on said bottom wall and including a compressed air flask havinga discharge opening in one end and a movably mounted valve closing thevent opening in said flask, a bracket mounted on said tube adjacent theopening in the latter, a lever pivotally mounted intermediate its lengthon said bracket and having one end engaged in the recess in said stem, alink connecting the other end of said lever to said valve, and anexplosive charge in the space within said receptacle surrounding saidtube, said mine being entirely free of magnetic materials.

References Cited in the iile of this patent UNITED STATES PATENTS NumberName Date v1,682,560 Gruber Aug. 28, 1928 2,377,174 Parker May 29, 19452,438,307 Taylor et al Mar. 23, 1948 2,450,407 Bartgis Oct. 5, 19482,514,401 Lilijegren July 1l, 1950 FOREIGN PATENTS Number Country Date866,769 France June 9, 1941

